Bits or picks for mining spray water into the coal vein to suppress dust and cool the work area. Picks of this type are described in U.S. Pat. No. 4,664,450 to Radford. Typically, the picks are mounted in an array on the rim of a power-driven cutting wheel. The fluid usually water, under pressure, is supplied to holders mounted on the periphery of the drum. The picks have an inlet connected to the water supply and an outlet which directs water to the work area. Typically, the holder includes a socket within which the shank of the mineral mining pick is received. The pick should rotate in the socket to maintain the sharpness of the hard cemented carbide cutting insert located at the tip. A tubular spigot or water tube located within the socket extends longitudinally toward the open end. The inner end of the spigot communicates with a fluid supply passage and the outer end extends into an axial opening in the pick. Various techniques for delivering water to the axial opening in the pick are known in the prior art. Similarly, various means are known to retain the pick in the socket of the holder during cutting while permitting rotation of the pick.
The prior art has located outlet ports at various locations on the peripheral surface of the head portion of the cutter bit. U.S. Pat. No. 4,405,178 illustrates a cutter bit having a plurality of outlets or nozzle-like exit orifices adjacent the cemented carbide cutting tip. Other conventional prior art devices have located the outlet ports at a position spaced from the carbide insert and facing in a forward direction parallel to the axis of rotation. Such picks taper outwardly from the tip to a radially projecting ledge. The ledge has a forwardly facing surface on which the outlet ports are mounted. Since the ledge is perpendicular to the axis of rotation of the bit, the ports face forwardly directly into the work area. As the bit attacks the work to be cut, detritus flows rearwardly over the head portion of the pick. The outlet ports tend to plug so that proper delivery of water to the work area is prevented. If water delivery is used intermittently, the outlet ports tend to clog with packed detritus during the cutting interval when the water supply is shut off. When the water delivery is resumed, the clogged outlet ports can misdirect or even prevent the spray from reaching the work area. Thus, the picks can be rendered ineffective prior to the end of their normally useful life.